Martin Luther King Jr. was the most important leader of America’s civil rights movement and a great orator who’s words helped sow the seeds for peace and equality. King is most remembered for his powerful “I Have a Dream Speech” delivered in 1963 during the March on Washington, but he also delivered dozens of additional speeches.

As the nation prepares to celebrate what would have been King’s 83rd birthday, remember his life and legacy in this sampling of 15 of his most powerful quotes.

“I have a dream that my four little children will one day live in a nation where they will not be judged by the color of their skin but by the content of their character.”

“Let us not seek to satisfy our thirst for freedom by drinking from the cup of bitterness and hatred.”

“The time is always right to do what is right.”

“Darkness cannot drive out darkness, only light can do that. Hate cannot drive out hate, only love can do that.”

“I can never be what I ought to be until you are what you ought to be. This is the way our world is made. No individual or nation can stand out boasting of being independent, we are interdependent.”

“Freedom has always been an expensive thing. History is fit testimony to the fact that freedom is rarely gained without sacrifice and self-denial.”

“Injustice anywhere is a threat to justice everywhere. We are caught in an inescapable network of mutuality, tied in a single garment of destiny. Whatever affects one directly, affects all indirectly.”

“A man who won’t die for something is not fit to live.”

“The ultimate measure of a man is not where he stands in moments of comfort and convenience, but where he stands in times of challenge and controversy. The true neighbor will risk his position, his prestige, and even his life for the welfare of others. In dangerous valleys and hazardous pathways, he will lift some bruised and beaten brother to a higher and more noble life.”

“A nation that continues year after year to spend more money on military defense than on programs of social uplift is approaching spiritual death.”

“We must accept finite disappointment, but we must never lose infinite hope.”

“The nonviolent approach does not immediately change the heart of the oppressor. It first does something to the hearts and souls of those committed to it. It gives them new self-respect; it calls up resources of strength and courage that they did not know they had. Finally it reaches the opponent and so stirs his conscience that reconciliation becomes a reality.”

“Freedom is never voluntarily given by the oppressor; it must be demanded by the oppressed.”

“When evil men plot, good men must plan. When evil men burn and bomb, good men must build and bind. When evil men shout ugly words of hatred, good men must commit themselves to the glories of love. Where evil men would seek to perpetuate an unjust status quo, good men must seek to bring into being a real order of justice.”

“This is the great new problem of mankind. We have inherited a large house, a great ‘world house’ in which we have to live together– black and white, Easterner and Westerner, Gentile and Jew, Catholic and Protestant, Muslim and Hindu– a family unduly separated in ideas, culture and interest, who, because we can never again live apart, must learn somehow to live with each other in peace.”

“The past is prophetic in that it asserts loudly that wars are poor chisels for carving out peaceful tomorrows.”

To read transcripts or listen to audio recordings of King’s most famous speeches, visit thekingcenter.org.